Alcohol dependence is a prevalent disease with substantial morbidity and mortality. Detoxification and psychosocial therapy provide the basis of treatment; in addition, pharmacotherapy is becoming widely accepted. Administered orally, naltrexone, a potent opioid antagonist, has been shown to reduce relapse to heavy drinking in alcohol dependent patients, decrease the number of drinks consumed when relapse does occur, and promote abstinence. Naltrexone has been reported to reduce both craving and the reinforcing euphoric qualities of alcohol.
Although naltrexone has been shown to be effective as a maintenance agent in the treatment of alcohol dependence, a major limitation of its utility can be poor adherence to therapy. In the treatment of alcohol abuse, oral naltrexone must be taken on a daily basis. In a clinical trial comparing oral naltrexone to placebo, greater than 40% of patients treated with naltrexone were noncompliant with the daily oral regimen. In medication-noncompliant patients relapse to clinically significant drinking was similar to placebo treated patients and significantly higher than the rate observed with medication-compliant patients.
Polymorphs, solvates and salts of various drugs have been described in the literature as imparting novel properties upon the drug. These polymorphs can have different solubilities, stabilities and processing characteristics, presenting opportunities and challenges.